Oil burner



Aug. 26,1930. J GOOD r AL, 1,174,137 on. BURNER v Filed July 8`, 1925TRnNs FORMER OIL MVT SEfn/o No Tan' INVENTO Patented Aug. 26, 1930UNITED STATES PATENT oFFIcE JOHN GOOD, F GARDEN CITY, AND ELLIOT O.SEAVER, OF MINEOLA, NEW YORK, ASSIGNORS TO GOOD INVENTIONS CO., OF NEWYORK, Y., A CORPORATIONVOF NEW YORK Application filed July 8,

The invention relatesto oil burners of the type intended for househeating purposes, although useful elsewhere, and its object is toprovide a safe automatic control system u for such apparatus whereby,among other things, it is made impossible for the combustible and anigniting temperature to coexist in the combustion space ofv the furnace,except according to the propersequence or during normal combustion, andwhereby, especially, the resumption of the burner-operating current,after an interruption caused by thermostat control or otherwise, cannotproduce delivery of fuel or the operation of the ignition means untilafter 1 the lapse of a period of time, say ten minutes or so, suiicientto allow the cooling of all internal parts of the furnace to belowignition temperature. The invention involves various features ofcontrol, looking toward the avoidance of accident and dangerousconditions, all of which will be made apparent in thc followingdescription, and man),1 of which will be recognized as capable ofapplication with advantage to existing control systems of other types.'Y v In the accompanying drawing Figure 1 is a general diagram of thepreferred form of the new system, Figure 2 being a detail elcvation ofthe timing. device or servo-motor, and Figure 3 a diagram of the controlcycle.

The burner proper with which this invention is adapted for use may be ofany desired type and is diagrammatically representd in the drawings ascomprising a fan blower l and a fuel spray nozzle 2 within asuitablehousing, the fan being driven by an electric motor 3. An igniter for theburner is indicated at n hot wire igniter, which becomes incandescentwhen energized, although any suitable means of ignition can be easilybrought within the control ofthe present system by suitable adaptation.As al means of avoiding oil leakage when the burner" motor is notenergized, an oil valve is ordinarily applied to the oil line to theburner, arranged to close whenever the burner motor stops running.

.50 Such an oil valve is controlled by the electro- 4, being in thiscase an electric resistance orv OIL BURNER 1925. Serial No. 42,145.

the burner except when the latter is opera-tf I ing and then only to stoit and has no control over the timing devlce except to start it inaction. This timing deviceA starts the burner motor and then shifts the'control of the lat-ter over to the thermostat, and forbids resumption ofburner operation until after the cooling period has intervened. The roomthermostat in the present ycase is an ordinary bi-metallic strip adaptedto Hex to the right as it cools and make a double contact on suchmovement, one-contact (22) being made directly by the end of thebi-metallic arm itself and the other (28) by means of a flexible fingersecuredt' and moving with it; the design will be clear from the diagram.The double contact is preferred but a single 'contact thermostat 'could'be made to sufce 'perature is to be controlled, the present vsystemcould also be controlled by variation of pressure as by means of a,so-cal'led pressurestat adapted to respond either directly or 1ndirectlyto changes of boiler pressure. For convenience in this description andin the claims all such heat or pressure-sensitive devices are includedin the term room thermostat.

fore it functions to start or permit the start- P ing of, the burnermotor. Within the category of devices suitable for this purpose areincluded motors, thermostatic elements and dash pots when suitablycontrolled and regu- The timing device above referred to can be lated.Preferably the timing device cnstituted of a member having a fixed cycleand the present case,

` at contact point 32.

so organized that when once started, its full cycle must be carried outbefore it can repeat any function. 'A part of such cycle is' allotted tothe energiz'ation of thegburneroperating motor and its igniter andappurtenant parts, and the rest, and greater part, is merely timeconsuming. By this division o f the cycle, two successive motorenergizations cannot occur without a time interval between them which ismade long enough to allow all heated parts in the furnace to cool downto below an igniting temperature, thereby precluding the possibility ofan explosion on the resumption of the -action of the igniter or of thefuel delivery. The delay thus involvedand which may be teni minutes ormore, is found to be unobjection able in an automatic system andrepresents a positive assurance of safety. In the present case, thet1m1ng device is a small motor, herein called and marked theservo-motor. `ItVA 1s geared through appropriate reduction gearing toimpart a slow drive to a commutator 6 and two adjacent cams 7 and 8, atthe rate of about one revolution in ten or twelve I nlnutes. These partsare yshown in elevation 1n Fig. 2 and their respective developmentsappear in the diagram of Fig. l as a matter of convemence in observingthe sequencel of operations.

The function of the lcommutator is to controlits own armature circuitand the igniter c1rcu1t. The function ofthe cam 7 is to lift or move theswitch armature 9 of the holding magnet 10 so vas to close the circuitgap at contact polnt 11.A When this armature has so been moved, the eldof the magnet 10 retams 1t closed, (provided the magnet`circuit 1s notopened elsewhere) independently of .further control by saidcam. When theholdlng armature is released it falls, by gravity in and closes thecircuit gap The cam 8 1s for the purpose of depressing a plunger orstriker 12 against a spring and releasing 1t so as to lcause it tostrike the switch armature 13 and knock it into its clrcult-closlngposition in which it, like the armature 9, 1s then held blt-beheld ofthe magnet 14:.v In itsv normal ondropped positlon, armature 13 is outpf the magnet fieldand cannot be closed bythe effect of the magnetalone. The magnet 14 is hereiny referred to as the motor switch magnet,in-

asmuch as the closure, .by its armature 13, of the gaps at contactpoints 15 completes the motor-operating circuit 16. This circui't,itwill be seen, is connected directly to the main supply leads 17 of thehouse circuit and ma be assumed to carry-the usual 110 volt cur' rent.Inasmuch 'as the function of the cams 7 and 8 is' merely to cause theirrespective thus they controlling circuit for the servo f motor. in

The high potential or house current 1s also used for igniting the burnerwher hot wire ignition is employed andthe ignition circuit in thepresent case is marked 21 being connected to leads 19.

Assuming that the system is out of action, commutator 6 occupies theposition, with respect toits several brushes, which `is indicated inFigure 1. The three conducting strips 23, 24 and 25 of the commutatorare all connected together, as indicated by dotted lines, and two ofthem, `23 and 24, are engaged with their respective brushes whereby acircuit will be seen to be ,established which in' in rotation. The shortarm of the thermostat closes the gap at its contact 28 slightly beforeor coincidently withy the closure of gap at 22 and its effect is toestablish, but not to complete, a circuit which includes the secondaryof the transformer, the two magnets above referred to, .the gap (open)at 11, armature 9 and Wire 27 back to the thermostat.-

This circuit is referred to as a holding circuit, since its principalfunction is to hold both armatures' in circuit-closing positions, but itis open, or uncompleted, when the commutator starts to rotate. Thiscircuit `is shown by the heavy line in the diagram.

The lirst etl'ect of the rotating commutator is to bring the commutatorstrip 30 into contact with the two adjacent brushes of the ignitercircuit 21 and thus close the igniter circuit; this mayoccur in aboutfteen seconds after the servo-motor'has started; no

other action results from thiscircuit closure, but the igniter, if aresistance element, begins y to get hot. Before theigniter strip 30 has'passed from under its brushes, the cam 7 will have revolved to such anextent as to lift its armature and thereby close the gap at 11 andarmatures to be-placed in circuit-closing po'- thus complete the holdingcircuit above refor as long as the room thermostat maintains its contactat 28. The cam 8 will also have depressed the plungei 12 and shortlyafter the closure of the holding circuit by cam 7, will have releasedthe plunger so as to cause it to strike t'he'motor switch armature 13and v close the motor circuit already referred to.

\Vhen thus thrown into circuit-closing position the motor switcharmature is put into the feldof its magnet as already explained and isthereafter retained in such position independently of any furtheroperation of the cam 8 or the commutator. That is to sav, theservo-motor has started the burner motor and completed the holding andmotor circuits and at the same time has relinquished lall furthercontrol of thosey parts, shifting such control to the 'holding circuit,that is to say, to the room thermostat. If the latter should open thegap 28, both armatures would drop and the burner would stop. Some 125seconds have been consumed in the rotation of the commutator necessaryto start the burner-operating motor and during that period the igniter 4will have attained an igniting temperature so that en the delivery offuel ignias of the servo-motor; closure by it of the gap at y22 can haveno effect because the commutator brush at theother end of wire 26 is onthe dead part of the commutator; closure of the gap at 28 can also haveno effect because the holding circuit is broken by the gap at 11fa11d,as already described, that-.Gap cannot be closed until the armature 9 islifted by the cam 7 and even if1 the gap at 11 should be closed in` someabnormal f way, the burner motor could not be started without theassistance of cam 8 and its spring/plunger. Thus afterevery period ofburner action, or conversely, before any second igniter action, theremust intervene a cooling period long enough to forestall fuel deliveryinto a furnace chamber hot enough to ignite it; once the burner hasstarted it can-be stopped on the call lof the room thermostat but itcannot be restarted until the next stroke of the switch closingplunger'. The purpose in closing the switch by hammer stroke is toprevent any possibilty of the servo-motor stopping in a switch-closingposition and thus holding the switch closed. p f

Any momentarycessation of the main current supply has the same effect asopening of tion occurs, followed by normal combustion.- gap 28 by thethermostat, since the de-ener- The commutator strip .3 0 is preferablylong enough so that it does not run out from under its brushes for someseconds after the burner motor has started, in order to make ignitioncertain. ,A

Thereafter when the commutator strip 24 has moved out of contact withits brush, the

motor armature circuit above referred to is interrupted and the'servo-motor stops. It remains stopped for so. long as the holdinglcircuit is active or the burner motor isrunis connected tothe lowercontact`32 of the the holding circuit, (le-energizing magnets 10 and 14,and releasing both of their armatures, which -discontinues the burneroperating current. vRelease of the holding armature 9 closes the .gap at32 and thereby completes a servo-motor arma-ture circuit through wire31, strips -25 and .23 connected back through wire 27 to the armature 9.This causes the servo-motor to resume operation and complete therotation cycle of the commutator,

rotatingit until the brush of wire 31 runs off the end of strip 25 whichis the normal or staltionary position, indicated in the diagram.

The time consumed in such continued or second rotation is approximatelyten minutes and during that period the room thermostat is entirely outo'f control of the burner as well gizingy of the transformerde-energizes the magnets 1() and 14, their armatures drop and can onlybere-closed after the commutat-orV has revolved to such extent as may benecessary to bring the cams 7. and 8 again into action upon them. If thecurrent failure should occur, exactly at themoment of the cam closure ofthe gap at 11, no untoward effect can be produced on resumption, be-

` cause the motor switch armature 13 has not yet been closed, and asufcient time interval intervencs between the operation of the two camsin any event to allow the igniter to reach an igniting temperaturebefore theburner comes on. At all other times failure'of the currentsupply results in the opening of gap 11 which cannot be closed until theservomotor has performed the cooling period part of its cycle,represented by the length of commutator strip 25.

The sequence of the several operationsis illustrated in the cycle.diagram of Fig. .3 wherein it will `be seen that the resistance igniteris energized shortly after the timing device nor servo-motor startsrotation, and that some A119 seconds elapse before the burner motor 1sset in action. This interval is to allow the rcsistance'igniter toattain an igniting temperature before the fuel strikes.

between both.

time periodindicated from the servo stop position to the start positionmay be, as stated, about ten minutes to serve as a'cooling period forthe interiorof furnace parts. .In-

5 asmuch as the commutator mechanism roby cam.8, as already ekplained.

Icease just at the moment ofclosing ofgap 11 It will be seen that whilethe system as' above described uses a double-contact thermostat, the twocontacts 28 and 22 could, if

desired, be consolidated into one.

The switch device diagrammatically indicated at 33 will be understood tobe the usual trip switch adapted to operate'in the case of leakage ofoil, for the purpose of opening the v main current supply circuit untilre-set by` hand.A A

We claim g 1. A burner control system comprising a burner motor,4atiming device adapted to :m start the same, a room thermostat adaptedto start said timing device, and means enabling the thermostat 4to stopsaid motoa` independently of the timing device.

2. A burner control system comprising a burner motor, a timing deviceadapted to start the same; a room thermostat adapted to start saiddevice and stop/ said motor independently of the timingdevice,v andinterrelated connections between said thermostat 40 and timing devicewhereby the latter interposes a cooling period between successi ve motorstartings.

y 3. A burner control system comprising 4a burner motor, a timing deviceadapted to lclose 5 the switch thereof, aroom thermostat-adaptedtoastart said device in action and a Cir- .cu'it whereby the.thermostat holds said switch closed.

4. A burner control system comprising a burnr motor,a motor switchtherefor,'a holding clrcuit and magnetic means energizedthereby adaptedto hold said switch closed but lncapable of closing it, a timing deviceadapted for closing said switch and a room thermostat for 'startingsaid' timing device and controlling said circuit.

5. A burner control system comprsing a burner motor,.a motor switchtherefor, a

m holding circuit -and magnetimens'energized .thereby adapted `to holdsaid switch closed, but incapableof closing it, a timing device arrangedto lclose said switch but iii-j capable of holding it closed and ofopening it,

'55 and a room thermostat in control of said cira burner motor, anelectromagnet eratin motor, igniter and a room thermostat.

norma ly out of immediate control of said motor, in combination withmechanism started by the thermostatic action, adapted to energize theigniter and motor, and having means interposing a cooling intervalbetween successive igniter energizations, and means whereby control ofthe burner-motor, when started, is transferred' from said mechanism tothe room thermostat.

8. A burner control system comprising the combination withaburner-operating motor, an igniter and a room thermostat normally outof immediate control of said motor, of mechanism normally controlled bythe thermostat, arranged to energizelirst the igniter and then-the motorand interpose a cooling interval betweensuccessive energizations of saidigniter, and a holding circuit,inclu ding the `thermostat, establishedby the action of said mechanism.-

9. In an electric burner control system, a burner motor and an operatingcircuit therefor, an electromagnetic motor switch for said circuit, aroom' thermostat adapted to close a gap in the motor switch circuit anda timcuit which includes said magnet and thermostat, whereby the latteris`in direct control of said magnet. l 11'. Inan electric burner controlsystem, a burner motor, an electromagnet to `control the same, a roomthermostat controlling a gap in the magnets circuit, a timing devicealso controlling a gap in said circuit, and acircuit for startingsaid-timing device in action having a thermostat.

12. In an electric burner-contrl system,

the" same, a room thermostat' controllingv a gap in the magnets circuitatimingr device also controlling a gap in said circuit, a circuit forstarting said timing device in action havinga gap also controlled bysaid thermostat, and means whereby failure of saidI gap also controlledby said y o lcontrol `ing device also controlling a gap in said magnetscircuit also starts said timing 'device.

13. In a-f.. burner control system, a b urner 'motor, a motor switchtherefor, a room thermostat, a timing device set in motion by the actionofsa'id thermostat and adapted to close said switch and stop its ownmot-ion, independently of said thermostat, while the 'burner motor isenergized, and means whereby said timing ldevice continues its motionwhen the burner motor is deenergized.

14. In a burner control system, a burner motor and igniter, a holdingcircuit for the burner motor, a servomotor adapted to energize saidigniter and burner motor, establish said holding circuit and' then stopvits own motion, and meanscontrolled by said holding circuit for causingcontinued operation of said servomotor when said holding circuit isbroken.

15. In a burner control system, a circuit including two magnets, thearmature for one of said magnets being adapted to close said circuit, adevice to 'move said armature tol circuit closing position, a burnermotor circuit controlled by the armature of the other magnetv and meansfor causing the latter armature to close the burner motor circuitaftersaid magnet circuit has been closed.

16. In a burner control system, a room thermostat; a circuit containinga lgap controlled by said thermostat and also containing a holdingmagnet and a gap vadapted to be held closed by said magnet, eleetromotormeans adapted for closing said last mentioned gap but incapable ofopening it, AYand means whereby the room thermostat sets said means inaction.

a double-contact room thermostat, a timing device started in action by acircuit through one of said contacts and a holding circuit including theother thermostat contact and established by the. action of said timingdevice. p 19. In a burnerv control system, a burne motor, and a doublecontact room thermostat normally out of direct control of said motor, incombination with an electrically operated vtiming device having acircuit including one .o f said thermostaty contacts wherebyj it isstarted, a holding circuit including the other ios'fffof said contacts,a magnet in sald holding circuit and means whereby said magnet controlsthe operating current to said motor.

20. In a burner control system, a burner motor, a resistance igniter anda room thermostat, in combinationv with a servo-motor, and meansoperated thereby for successively causing energization of the igniterand motor, said means including amagnet, an armature thereforand meansdriven by the servo-motor. for operating said armature. 21.- In a burnercontrol system, a burneroperating motor and a resistance igniter, amagnet to control the motor, a room thermostat adapted 4to close a gapin the circuit of said magnet and a timing device adapted to close theigniter circuit and also controlling a gap in said magnet circuit. i

22. In a burner control system, the combination with a burner motorcircuit and an igniter, of a room thermostat circuit, a timing devicestarted in response to closure of the. room thermostat circuit,connections whereby the igniter, and, after an interval, the burnercircuit are energized by the timinw device, said timing device beingadapted subsequently to cause de-energization of the igniter and meanswhereby opening of the thermostat circuit stops thegmotqr.

23. In a burner control system, the combination of a room thermostatcircuit-and a timing device, means whereby the room ther- -mostat startsthe burner through said timing device and means whereby opening of theroom thermostat circuit stops the burner independently of the timingdevice.

24. In a burner control system a room thermmostat circuit, a burnermotor started in re sponse to closure of said circuit and stopped inresponse to opening thereof, an igniter energized in response to closureof the room thermostat circuit, means for interposingr a delay betweenthe energization of the igniter and starting of the burner motorandmeans for le-energizing the igniter independently of the roomthermostat circuit.

25. In a burner control system, a room ther.- mostat circuit, a burnermotor started in response to closure of said circuit and stopped inresponse to opening thereof, an igniter, and means for interposing adelay between successive motor energizations.

In testimony whereof, we have signed this specification.

JOHN GOOD. ELLIOT O. SEAVER.

' y DISCLAIMER 1',774:,137*.`.-John Good, Garden City, and Elliot 0.Seaoer, Mineola, N. Y. OILd BURNER. Patentdated lAugust 26, 1930.-Disclaimer filed August 14, 1935, ly the assignee, Good Inventions 0o.ereby enters this disclaimer, to Wit:`

(1) From claim 3, all burner control systems wherein the room thermostatholds the burner motor switch closed through the agency of the timingdevice.

(2) From claim 25, all burner control systemsexcept those wherein theigniter is rendered active in response to the closure of the roomthermostat.

[Oficial Gazette Sptember 10, 1935.]

